The present invention relates to light fixtures in general, and more particularly to light fixtures involving light emitting diodes (LEDs).
LED light sources offer significant advantages over incandescent lights in terms of energy efficiency and useful lifetime. The LEDs can be provided in continuous strips of diodes which enable mounting within compact light fixtures which may be utilized in a wide range of applications. LED performance is temperature dependent, and can suffer at elevated temperatures. LED light fixtures thus often make use of passive heat sinks to dissipate the heat generated internally. Because the strip of individual LEDs which serves as the LED fixture's light source is comprised of multiple point sources, the fixture is commonly provided with an extruded plastic diffuser or cover lens which attaches to an extruded aluminum housing which holds the LED strip. Sometimes the housing itself acts as the heat sink for the LEDs.
Retention of the cover lens in place on the fixture is an important aspect of an LED light fixture. If the cover lens is too loose, it runs the risk of separating from the light fixture, often located overhead. If it is too tight, it can be difficult to remove for servicing. Many LED fixtures with extruded housings attach the cover lens by disposing outwardly extending portions of deflectable legs of the cover lens within inwardly facing slots or grooves of the main housing. However, with the typical tolerances of extrusion manufacture, if this connection is not tight enough, the cover lenses can fall off the fixtures. Moreover, because forces are applied to the housing itself when the cover lens is removed or reinstalled during service, this lateral movement on the main housing risks cracking in the drywall within which a fixture is mounted, especially where the fixture is mudded in place.
Furthermore, light fixtures can be mounted in many fashions, flush to the surface of a wall ceiling or floor, in hung ceilings or drywall ceilings, suspended, mounted to project from a wall or ceiling, for downlighting, uplighting, or wash lighting, and in other fashions. Minimizing the number of distinct parts to accommodate all these options is an important objective. In addition, construction projects are often subject to change, and pose a logistical challenge to fixture suppliers to provide light fixtures of the right type and size to suit the needs of the moment.
What is needed is an LED light fixture that securely retains its cover lens while permitting convenient servicing with little risk of cracking drywall installations, and which has wide variability of installation mode with a minimum of parts.